"Innately" is being used in that post in the sense of being a fundamental personality trait or a strong predisposition (as in "Correspondance Bias", to which that post is a followup). And fundamental personality traits and predispositions do exist — including some that actually do predispose people toward being evil (e.g. sociopathy) — so, although the phrase "innately evil" is a bit dramatic, I find its meaning clear enough in that post's context that I don't think it's a mistake similar to "fundamentally moral". It's not arguing about whether there's a ghostly detachable property called "evil" that's independent of any normal facts about a person's mind and history.